The proposed research will examine the surface polysaccharide antigens of newly isolated strains of Neisseria gonorrhoeae to determine if they differ in chemotype and/or serotype from the antigens of laboratory subcultured strains. Lipopolysaccharide (LPS) will be extracted from a number of freshly isolated strains and its qualitative and quantitative chemical composition determined. The strains will also be examined for the presence of capsule. Purified antigens will be used to raise immune sera in rabbits. Immune sera will also be obtained from humans. These sera will be used to investigate the serology of the gonococcus and its antigens. The application of the purified antigens to a serotyping scheme and serological tests will also be investigated.